If god wants man to be monogamous, why did he create men as disposable in nature?

One man can impregnate hundreds of women in a week or a month. Men produce millions of sperm while women produce one egg. Women can only get pregnant once every 9 months and this means they have to be super selective about who they mate with. Humans are sexually dimorphic, meaning males inter compete with each other for access to mating, this leads to wars and violence. The penis is designed to scoop out other male sperm, everything points to us being a polygynous species sexually.

There's a maple tree in my front yard that dispenses thousands upon thousands of "helicopters" in the spring. There is no suggestion of the valuelessness of the tree or its reproductive pattern.

Nature seems designed for successful reproduction against all odds. Nature seems designed for prolific possibilities across an environment possibly antagonistic to reproductive success.

Homo sapiens are part of this ecosystem. Males share a characteristic we see in abundance in flora and fauna: abundance to result in success. This doesn't seem to be a design flaw.

So now your real question is about monogamy. If survival as a species is the goal, some rules to quell wars and violence might be the path of wisdom. If males are truly dimorphic and violent, then social constructs such as monogamy lead to survival as communities and clans.

And if God is the source of morality, as the Bible implies, then God is interested in our wellbeing, peace-making, and ultimately our survival. Creating us with the sex drive leads to reproduction, but creating us with a conscience leads us to understand and experience noble character traits like love, faithfulness, and tolerance, and to eschew traits like envy, pride, greed, and treating each other like animals.